The present invention relates to a unitary interlocking frame for use with a storage file container to allow a plurality of containers to be stacked and locked from relative movement.
File and storage containers of the lightweight, fiberboard type are widely used in homes and offices and generally include a fiberboard shell that receives a drawer that can be slidably removed from the shell to provide access to materials stored in the drawer. Frequently, the containers are stacked on top of each other to provide a multiple compartment storage assembly. One potential problem with vertically stacking the containers is that they may become dislodged or move relative to other vertically adjacent containers when the user attempts to open and close a drawer. Another problem with stacking such containers is that the drawers in the lower containers may be difficult to open due to bending of the shell near its front as a result of the weight from the vertically adjacent filled containers.
One solution to these problems has been to provide a device to interlock the containers together as a unitary assembly so that the containers can be vertically stacked. The devices used for this purpose have taken the form of metal strips or rims that are attached to the sidewalls of the containers and are provided with extensions for joining vertically adjacent containers together. Generally, at least one strip is provided near the front of the shell to minimize bending of the shell. In addition to being unsightly, stacking devices of this type may be unduly expensive in comparison with the low cost of the fiberboard containers with which they are used.
Another solution has been to provide a plastic frame that surrounds the front of the shell. To interlock the containers, interlocking clips are provided to lock vertically adjacent shells or frames as well as horizontally adjacent shells or frames so that the containers can be vertically stacked. The clips, however, increase the number of parts and thus cost of an interlocking system. In addition, the clips may become lost.